It is known to use inorganic acids for eliminating of corrosion products, scale and scoria (Spring: Scouring of Metal Surface; 1964). However they have a negative effect on the health and the environment, attack the metals and cause rapid development of fresh corrosion.
There is also known a composition for scouring surfaces from organic and inorganic impurities which contains an inorganic acid, sodium benzoate and a surfactant Bulgarian Authors Certificate BG 34262. It comprises in addition a product from preliminary hydrolysis of cellulose by the sulphate method, dodecylbenzolsulphonic acid, streptotricynic antibiotic 741(lavendotricyne) produced by strain Actinomyces Lavandulae, sodium tetraborate, ethoxylated alkylphenol with 10 ethylene oxide moieties per molecule and a condensate of naphthalene sulphonic acid with formaldehyde or ethoxylated fatty alcohols with chain length C.sub.10 -C.sub.16 in the following weight ratios:
preliminary hydrolysate--95.00 to 85.00 PA1 sodium benzoate--0.20 to 0.50 PA1 dodecylbenzolsulphonic acid--0.40 to 2.50 PA1 lavendotricyne--0.50 to 0.70 PA1 sodium tetraborate--0.40 to 0.50 PA1 ethoxylated alkylphenol with 10 mol/mol ethylene oxide--0.40 to 1.20 PA1 condensate from naphthalene sulphonic acid with formaldehyde or ethoxylated fatty alcohols C.sub.10 -C.sub.16 --0.40 to 2.50 PA1 inorganic acid:phosphoric or sulphuric 2.00 to 5.00 PA1 dry residue at 80.degree. C.--60 to 80 g/l; at 105.degree. C.--50 to 80 g/l PA1 acetic acid--1.5 to 2% PA1 formic acid--0.2 to 0.5% PA1 furfural--0.3 to 0.7% PA1 reducing substances--2.8 to 3.6% PA1 monosaccharides--1.9 to 3.2% PA1 dextrin--0.8 to 1.5% PA1 brominating agents--1.4 to 1.8% PA1 Waste product of fodder yeast--60 to 95% PA1 citric acid--2 to 6% PA1 ammonium citrate--0.1 to 10% PA1 sulphonated ricinic oil--0.0 to 4% PA1 aqueous solution of sodium gluconate--0.0 to 20% PA1 inorganic acid--0.0 to 15% PA1 Reducing agents--0.06 to 0.1% PA1 phosphates--0.01 to 0.02% PA1 ammonium sulphate--0.2 to 0.4% PA1 furfural--0.0 to 0.06% PA1 yeast--0.0 to 0.1 g/l PA1 prevention of the negative effect on health and environment; PA1 the metal is not attacked by the composition; PA1 prevention of fresh corrosion by the formation of a lasting film on the surface that is stable at atmospheric conditions; PA1 reduced number of utilized components; PA1 no use is made of problematic components; and PA1 it consumes a waste product in manufacture of fodder yeast.
The preliminary hydrolysate, is an aqueous extract at high temperature of wood which is produced by preliminary hydrolysis by the sulphate method in order to obtain cellulose for viscose fibers. It is characterized by the following composition:
The hydrolysate has a specific weight at 20.degree. C. of 1,015 to 1,035. The disadvantage of this composition as described is its multicomponent nature, the use of some problematic substances and the fact that when washed the cleaned items tend to corrode anew.